Toxic air pollutants are poisonous substances in the air that come from natural sources (for example, radon gas coming up from the ground) or from manmade sources (for example, chemical compounds given off by factory smokestacks) and can harm the environment or your health.
Subsequently, Scorpius X-1 was discovered in 1962 by a team, under Riccardo Giacconi, who launched an Aerobee 150 sounding rocket carrying a highly sensitive soft X-ray detector designed by Frank Paolini.
Discovery of Iridium. Iridium was discovered in 1803, by English chemist Smithson Tennant in London. He found it in the residue left when crude platinum had been dissolved in aqua regia (a mixture of hydrochloric acid and nitric acid). Smithson Tennant also discovered osmium at the same time.ource: Iridium is found in natural alloys with platinum and osmium in alluvial deposits. Commercially, iridium is recovered as a by-product from the nickel mining industry. Isotopes: Iridium has 34 isotopes whose half-lives are known, with mass numbers from 165 to 198.